In analog system the data is transmitted in
form of analog signal.
The analog signals are the signal in witch the
amplitude is varying with the time
Amplitude is varying
In digital system the data is transmitted with
the use of digital signal.
Digital signals are signals which has only
some discreet value mainly two, ‘0’ & ‘1’.
Voice Calls Only
• Services included:
Mobile radio telephone systems preceded
modern cellular mobile telephony technology.
Since they were the predecessors of the first
generation of cellular telephones, these
systems are sometimes retroactively referred
to as pre cellular (or sometimes zero
It is ah half duplex system.
These early mobile telephone systems can under
stand in that they were available as a commercial
service that was part of the public switched
telephone network, with their own telephone
numbers, rather than part of a closed network
such as a police radio or taxi dispatch system.
These mobile telephones were usually mounted
in cars or trucks, though briefcase models were
also made. Typically, the transceiver
(transmitter-receiver) was mounted in the vehicle
trunk and attached to the "head" (dial, display,
and handset) mounted near the driver seat.
Technologies used in pre cellular systems
included the Push to Talk (PTT or
manual), Mobile Telephone
System (MTS), Improved Mobile Telephone
Service (IMTS), and Advanced Mobile
Telephone System (AMTS) systems.
Push-to-talk (PTT), also known as Press-to-
Transmit, is a method of conversing
on half-duplex communication lines,
including two-way radio, using a
momentary button to switch from voice
reception mode to transmit mode.
For example, an air traffic controller usually
talks on one radio frequency to all aircraft
under his supervision. All can hear each
other's transmissions and those of the
controller, and take turns speaking,
using procedure words such as "over" and
Only voice calls
No data transfer
No text messages
Voice Calls Only
• Services included:
1G (or 1-G) refers to the first-generation
of wireless telephone technology, mobile tele
communications. These are
the analog telecommunications standards
that were introduced in the 1980s and
continued until being replaced
by 2G digital telecommunications.
The main difference between two succeeding
mobile telephone systems, 1G and 2G, is that
the radio signals that 1G networks use are
analog, while 2G networks are digital.
1G speeds vary between that of a 28k
modem(28kbit/s) and 56k
modem(56kbit/s), meaning actual
download speeds of 2.9KBytes/s to
On 1G the signals are transmitted in analog
So, it basically used for phone calls.
There were no facility to send text or data
It uses small bandwidth.
Mainly nit used for longer distance
communication. Because signal becomes
weak & becomes noisy.
GSM is basically depends on time division
GSM is a standard set developed by the European
Telecommunications Standards Institute (ETSI) to
describe protocols for second generation (2G)
digital cellular networks used by mobile phones.
This was expanded over time to include data
communications, first by circuit switched
transport(CSD), then packet data transport
via GPRS (General Packet Radio Services)
and EDGE (Enhanced Data rates for GSM Evolution
GSM networks operate in a number of
different carrier frequency ranges (separated
into GSM frequency ranges for 2G and UMTS
frequency bands for 3G), with most 2G GSM
networks operating in the 900 MHz or
1800 MHz bands.
One of the key features of GSM is
the Subscriber Identity Module, commonly
known as a SIM card. The SIM is a
detachable smart card containing the user's
subscription information and phone book.
Code division multiple
Data is encrypt on a single
CDMA is basically code division multiplexing.
In this the signal which is transmitted are
encrypt d into a specific code. And the
encrypted signal is transmitted over a
In CDMA a locally generated code runs at a
much higher rate than the data to be
transmitted. Data for transmission is
combined via bitwise XOR (exclusive OR) with
the faster code. The figure shows how a
spread spectrum signal is generated.
Have very low power output that is 0.2 watts
(compared to the GSM system) that use 1.5 to
3 watts, making batteries CDMA system more
durable. Requires lower transmit power, so
cell phone talk time may be longer.
Improve sound quality.
Cell phone talk time becomes longer.
Enable encryption of voice, data and video.
Advantages GSM-based technology is a broad
coverage and vast roaming both in the
country and even around the world, while
CDMA is still very limited.
No SIM card is Present.
So GSM is widely used than
The details of the roaming process differ among types of cellular networks,
but in general, the process resembles the following:
When the mobile device is turned on or is transferred via a handover to the
network, this new "visited" network sees the device, notices that it is not
registered with its own system, and attempts to identify its home network. If
there is no roaming agreement between the two networks, maintenance of
service is impossible, and service is denied by the visited network.
The visited network contacts the home network and requests service
information (including whether or not the mobile should be allowed to roam)
about the roaming device using the IMSI number.
If successful, the visited network begins to maintain a temporary subscriber
record for the device. Likewise, the home network updates its information to
indicate that the cell phone is on the host network so that any information
sent to that device can be correctly routed.
In wireless telecommunications, roaming is a general term referring to the
extension of connectivity service in a location that is different from the home
location where the service was registered. Roaming ensures that the wireless
device is kept connected to the network, without losing the connection.
• Services included:
2G (or 2-G) is short for second-
generation wireless telephone technology.
Second generation 2G cellular telecom
networks were commercially launched on
the GSM standard in Finland in 1991.
While radio signals on 1G networks
are analog, radio signals on 2G networks
are digital. 2G systems use digital signaling
to connect the radio towers to the rest of the
2.5G is basically using GPRS(General Packet
Radio Service) for data transfer.
GPRS could provide data rates from 56 kbit/s
up to 115 kbit/s. It can be used for services
such as Wireless Application Protocol (WAP)
access, Multimedia Messaging Service (MMS),
and for Internet communication services such
as email and World Wide Web access.
GPRS is part of a series of technologies that
are designed to move 2G networks closer to
the performance of 3G networks.
2G requires the phone to make a special
connection to the network before it can
transfer data (like making a voice call) which
can take up to 30 seconds. Because its data
transfer rate is still to slow.
GPRS (General Packet Radio Service) is a
method of enhancing 2G phones to enable
them to send and receive data more rapidly.
With a GPRS connection, the phone is "always
on" and can transfer data immediately, and at
higher speeds: typically 32 - 48 kbps.
2.75G is basically using (Enhanced Data rates for
GSM Evolution) for data transfer.
It is also known as EGPRS.
EDGE is considered a pre-3G radio technology.
EDGE increases the speed of each timeslot to 48
kbps and allows the use of up to 8 timeslots,
giving a maximum data transfer rate of 384
EDGE was deployed on GSM networks beginning
in 2003—initially by AT&T in the United States.
High speed internet
3G, short for 3rd Generation, is a term used to
represent the 3rd generation of mobile
The basic standard for 3G network is defined
by the International Mobile Telecommunications
- 2000 (IMT2000) specifications.
To meet the IMT-2000 standards, a system is
required to provide peak data rates of at least
2 Mbit/s for stationary or walking users, and
384 kbit/s in a moving vehicle.
However, many services advertised as 3G provide
higher speed than the minimum technical
requirements for a 3G service.
Recent 3G releases, often
denoted 3.5G and 3.75G, also provide mobile
broadband access of
several Mbit/s to smartphones and mobile
modems in laptop computers.
The communication spectrum between
400 MHz to 3 GHz was allocated for 3G. Both
the government and communication
companies unanimously approved the 3G
The first pre-commercial 3G network was launched
by DoCoMo in Japan in 1998.
3G was relatively slow to be adopted globally. In
some instances, 3G networks do not use the same
radio frequencies as 2G so mobile operators must
build entirely new networks and license entirely new
frequencies, especially so to achieve high data
The 3G standard is perhaps well known because of a
massive expansion of the mobile communications
market post-2G and advances of the consumer mo
phone. An especially notable development during this
time is the smartphone , combining the abilities of
a PDA with a mobile phone, leading to widespread
demand for mobile internet connectivity.
This are the technologies which are advance than
3g but cannot classified as 4G.
There are three technologies are came after 3G
They are not fully satisfied for the criteria of 4G.
But they are the steps for transition from 3G to 4G.
3G 3.5G 3.75G 3.9G
3.5G is a grouping of
disparate mobile telephony and data
technologies designed to provide better
performance than 3G systems, as an interim
step towards deployment of full 4G capability.
3.75G is mainly based on HSPA.
High Speed Packet Access (HSPA) is an
amalgamation of two mobile
telephony protocols, High Speed Downlink
Packet Access (HSDPA) and High Speed Uplink
Packet Access (HSUPA), that extends and
improves the performance of existing
3rd generation mobile telecommunication
The latest networks allows bit-rates to reach
as high as 168 Mbit/s in the downlink and 22
The first HSPA specifications supported
increased peak data rates of up to 14 Mbit/s
in the downlink and 5.76 Mbit/s in the uplink.
in the uplink.
This is the main difference between WCDMA
(3G) network & HPDA (3.75G) network.
Before 4G networks the operator provides
3.9G network, which is also called pre-4G
This is not classified as 4G because of it uses
some less bandwidth than full 4G networks.
But this the last step for the transition from
3G to 4G.
The bandwidth and location information
available to 3G devices gives rise to
applications not previously available to
mobile phone users. Some of the applications
1. Mobile TV
2. Video on demand
3. Video Conferencing
5. Location-based services
6. Global Positioning System (GPS)
HD Video call
HD Mobile TV
Ultra High speed internet
New mobile generations have appeared about
every ten years since the first move from 1981
analog (1G) to digital (2G) transmission in 1992.
This was followed, in 2001, by 3G , in
2011/2012 expected to be followed by "real" 4G,
which refers to all-Internet Protocol (IP) packet-
switched networks giving Ultra Mobile
Broadband (gigabit speed) access.
In telecommunications, 4G is the fourth
generation of cell phone mobile
In March 2008, the International
communications sector (ITU-R) specified a set of
requirements for 4G standards, named
the International Mobile Telecommunications
Advanced (IMT-Advanced) specification, setting
peak speed requirements for 4G service at
100 megabit per second (Mbit/s) for high
mobility communication (such as from trains and
cars) and 1 gigabit per second (Gbit/s) for low
mobility communication (such as stationary
Data Throughput: Up to 3.1mbps Practically speaking, 3 to 5 mbps but
potential estimated at a range of 100 to
Peak Upload Rate: 50 Mbit/s 500 Mbit/s
100 Mbit/s 1 Gbit/s
packet switching packet switching, message switching
Wide Area Cell Based Integration of wireless LAN and Wide
CDMA 2000, UMTS, EDGE etc Wimax2 and LTE-Advance
Frequency Band: 1.8 – 2.5GHz 2 – 8GHz
Interoperability for Microwave
a wireless communications
standard designed to provide
30 to 40 megabit-per-second
data rates, with the 2011
update providing up to 1
Gbit/s for fixed stations.
WiMAX can provide at-home or
mobile Internet access across
whole cities or countries.
LTE (Long Term Evolution), marketed as 4G LTE,
is a standard for wireless communication of
high-speed data for mobile phones and data
terminals. It is based on
the GSM/EDGE and UMTS/HSPA network
technologies, increasing the capacity and speed.
LTE does not fulfill the requirements of 4G.
However due to marketing pressures and the
significant advancements that WIMAX,HSPA+ and
LTE bring to the original 3G technologies, ITU
later decided that LTE together with the
aforementioned technologies can be called 4G
he LTE Advanced standard formally satisfies
the ITU-R requirements to be
considered IMT-Advanced. and to
differentiate LTE-Advanced and WiMAX-
Advanced from current 4G technologies, ITU
has defined them as "True 4G"
Ultera high speed internet
High defination TV
HD video calling
Others as per 2G or 3G
5G network is assumed as the perfection level
of wireless communication in mobile
5G network is very fast and reliable.
A first remarkable feature of 5G network is
the broadband internet in mobile phones that
would be possible to provide internet facility
in the computer by just connecting the
Data sharing in 5G network is very easy. It
omits the condition of putting both mobile
face to face so that data could be shared.(Like
Comparison of Mobile Internet Access methods
Family Primary Use Radio Tech
LTE 3GPP General 4G
(in 20 MHz
(in 20 MHz
HSPA+ 3GPP Used in 4G
UMTS/3GSM General 3G